- Tantalum (Ta) is a refractory transition metal with atomic number 73, positioned in Group 5 of the periodic table, beneath niobium.
- Its electron configuration is [Xe] 4f¹⁴ 5d³ 6s², reflecting its place in the d-block. Each tantalum atom contains seventy-three protons, seventy-three electrons, and about one hundred and eight neutrons in its most stable isotope.
- Natural tantalum is composed mainly of one stable isotope, tantalum-181 (¹⁸¹Ta), while a rare isotope, tantalum-180m (¹⁸⁰ᵐTa), is a long-lived metastable nuclear isomer with an extremely long half-life (greater than 10¹⁵ years), making it effectively stable.
- Tantalum was first discovered in 1802 by the Swedish chemist Anders Ekeberg, who isolated it from mineral samples. Its name comes from King Tantalus of Greek mythology, as tantalum oxide would not absorb acid, just as Tantalus was unable to drink water despite standing in it. For decades, tantalum and niobium were confused because of their nearly identical chemical properties. It was not until the mid-19th century that the two were conclusively distinguished as separate elements.
- Physically, tantalum is a dense, hard, blue-gray metal with a very high melting point of 3,017 °C (5,463 °F) and a boiling point of about 5,458 °C (9,856 °F). It is extremely resistant to corrosion, even more so than platinum, because it forms a protective oxide layer (Ta₂O₅) on its surface. Tantalum is also an excellent conductor of heat and electricity.
- Chemically, tantalum is very inert, resistant to nearly all acids except hydrofluoric acid, which can dissolve it by forming soluble fluoride complexes. It typically exhibits an oxidation state of +5, forming compounds such as tantalum pentachloride (TaCl₅) and tantalum pentoxide (Ta₂O₅). The oxide is highly stable and used in electronic and optical applications.
- Tantalum’s most important use is in the electronics industry, especially in the production of capacitors and high-power resistors. Tantalum capacitors are small, reliable, and capable of storing significant electrical charge, making them essential components in smartphones, laptops, medical devices, and aerospace electronics. Its corrosion resistance also makes tantalum valuable for surgical instruments, medical implants (such as bone repair plates), and chemical processing equipment. Additionally, tantalum alloys are used in turbine blades, nuclear reactors, and military applications because of their strength and resistance to heat and stress.
- Biologically, tantalum is considered non-toxic and biocompatible, which is why it is used safely in medical implants. It does not react with body fluids and does not cause immune reactions. However, finely divided tantalum dust may cause lung irritation if inhaled.
- Environmentally, tantalum is relatively rare in Earth’s crust and is usually found in minerals such as columbite-tantalite (coltan), samarskite, and euxenite. Its extraction is concentrated in regions such as the Democratic Republic of Congo, Rwanda, and Nigeria, although Australia and Brazil also produce it. Unfortunately, tantalum mining, particularly coltan mining, has been linked to environmental damage and human rights issues in conflict regions, making its supply chain a subject of international concern.
